A more thorough explanation:

The continuation-application laches doctrine is a defense used in patent infringement cases. It is based on the argument that the patent holder intentionally delayed the issuance of the patent by filing multiple continuing applications that added new patent claims to cover products or processes that were marketed or used after the original application was filed.

For example, if a company filed a patent application for a new type of smartphone, but then filed multiple continuation applications to add new claims to cover features that were added to the phone after the original application was filed, a defendant in an infringement case could argue that the patent holder intentionally delayed the issuance of the patent to gain an unfair advantage.

This defense is also known as the prosecution-laches doctrine and is sometimes referred to as a "submarine patent" because it can be used to keep a patent hidden until it is advantageous for the patent holder to assert their rights.